LOS ANGELES (AP) — Andrew McMahon is hoping to raise a dollar for each young adult who is diagnosed with cancer each year. McMahon has launched The 72K Challenge through his Dear Jack Foundation to raise $72,000 by Dec. 31. McMahon says 72,000 people between the ages of 15 and 39 receive a cancer diagnoses each year and he says they are underserved by cancer research. McMahon himself was diagnosed with leukemia when he was 22. The money raised will be dedicated to cancer support charities for young people. You can donate or find out more at www.DearJackFoundation.com .